IRQL not less or equal and page fault in non paged area BSODs

For the past 1 month I've been getting Irql not less or equal and Page fault in non paged area BSODs every day several times and I have read so many posts for troubleshooting these errors and tried so many of them, from a clean windows 7 install to updating drivers, using driver sweeper and then updating again and what not..

But I just dotn seem to understand whats wrong. Tried understanding the minidumps using bluescreen view and I all could gather was some issue with ntoskernel.exe

Extra Info: The laptop is HP dv-7 running Win7-x64 and does seem to get pretty hot, especially when I'm playing Counter Strik 1.6 on Steam and crashes are much more frequent when I'm playing Steam CS 1.6

Okay djlaksh,
I have been struggling with heat issues with my laptop repairs of late. The CPU's seem fine with just Arctic Silver, but the graphics and north-bridge chips seem to need the silicone pads or the copper shims for proper heat dissipation